Computing machine



J. H. BARR.

COMPUTING MACHINE.

I APPLICATION FILED AUG. 5'. 1 915. 1,31 1,373, Patented July 29, 1919.

I3 SHEETSSHEET 2.

mvcwfoz J. H. BARR.

COMPUHNG MACHINE.

APPLICATION FILED AUG.5. 1915.

1,3 1 1,373. Patented July 29, 1919.

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E] n ma ntoz 1. H. BARR. COMPU'IING MACHINE.

APPLICATION FILED AWL-5.1915.

Patented July 29, 1919.

13 SHEETSSHEET 4.

J. H. BARR.

COMZUIING MACHINE.

APPLICATION FILED AUG.5. I9I5.

Patented July 29, 1919.

I3 SHEETS-SHEET 5- I :17.) i 37.; I

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J. H. BARR.

COMPUTING MACHINE. APPLICATIUN FILED A UGH'M 1915.

1,3 11,373. I Patented July 29, 1919.

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J. H. BARR.

COMPUHNG MACHINE.

APPLICATION man AUG.5. 1915.

Patented July 29, 1919.

l3 SHEETSSHEET 7 I. H. BARR.

COMPUTING MACHINE.

APPLICATION FILED AUG.5. m5.

.Patented'July 29, 1919.

13 SHEET.8SHEET 9.

Wane/om:

J. H. BARR.

COMPUTING MACHINE.

APPLICATION FILED AQGJ). 1915.

13 $HEETS-SHEET l 0.

Patented July 29, 1919.

J. H. BARR.

COMPUTING MACHINE.

APPLICATION FILED AUG-5. 1915.

1,3 1 1,37 3. Patented July 29, 1919.

13 SHEETS-SHEET 11.

Ha E15- J. H. BARR.

COMPUTING MACHINE.

APPLICATION FILED Aue.5. 191s.

Patented July 29, 1919.-

I3 SHEETS-SHEET l2:

Wu neompo l. H. BARR.

COMPUTING MACHINE.

APPLICATION FILED AUG.5. m5.

Patented July 29,1919.

l3 SHEETS-SHEET 13.

5] vwentoz 1%: names:

Q M Z w t a m quired in certain types of machine which mm: a. man, or new roux, I; Y.

COIPELHHG-KLCHHTE.

Bpeciflcation of Letters Patent.

Patented July 29, 1919.

Application filed August 5, 1815. 801111 Io. 48,821.

To all whom it may concern:

'Be it known that I, Join: H. BARR, a citi- Zen of the United'State-s of America, and a resident of New York city, county and State of New York, have invented certain new and useful Improvements in Computing- Machines, of which the following is a specification.

My invention relates to computing machines, and particularly to multiplication machines, and comprises a machine of the keyboard type, wherein. multiplication is performed by an operation, or series of operations, of a purely mechanical character, and without theuse of logarithmetic scales, curves, cams etc., and without successive operations of the same keys in any single multiplication operation, such as are reperform multiplication by a process of successive addition. The machine herein illustrated and described and embodying my invention comprises a multiplicand-receiving device,- which is referably a keyboard,comprising a lurahty of columns of keys, so arranged t at the multiplicand may be set up in this keyboard by depressing appropriate keys; and the machine also comprises a multiplier-receiving device, preferably consistin of a sin le. column of keys, which may o operate successively according to the various digits contained in the multiplier. The machine further com rises a. 'movin carriage carrying dial w eels or equiva ent indicating devices which show the roduct when obtained; and the machine furt er comprises an operating lever and mechanism operated thereby whereby, after the depression of each multiplier key, the

product of the multi lication of the previously set up multip icand, by the multiplier'digit corresponding to the multiplier key depressed, is obtained and transferred to the dial wheels; the carriage carrying such dial wheels being caused to move, after each multiplication by a multiplier digit, so that multiplication by the next multiplier digit will have an efiect on the product dials correspondin to the column or lace (21.6., tens, hundre 5, etc. to which t at multiplier digit belongs. The machlne further com rises suitable clearing mechanism whereby after performance of any complete multipl ing operation the machine ma be restore to normal position, with the dials at zero, preparatory to the next multiplication 0 eration. The construction of the ma chine 1s such t at if the product of one multiplication is to used as the multiplicand fora succeeding operation, such product multiplicand can be set up in, the multiplicand keyboard before the dial wheels are cleared; and thereby occasion for noting down an product in order that, after clearing of t e machine, it may be transferred as a 'multiplicand to the multi licand keyboard, is obviated. The mac 'ne further comprises means whereby a mistake in the depression of any multiplicand key, or any multiplier key, may be corrected before actuating the operating lever by which the tures of the machine will be pointed out hereinafter. 7

My invention comprises novel direct-acting multiplication mechanism; novel carrying or tens-transfer mechanism; novel means for giving due-effect to the column or order of each multiplier digit; a novel flexible keyboard; and other features all as hereinactual multiplication is effected. Other feaafter described and particularly pointed out a i. e., to theorder or place of that digit; to

provide for a plurality of carrying oper- 't e dial ations from each dial wheel to wheel next above or higher in order, asma and often will be required during multiphcation by a single digit; to provide 1m proved and simplified and' accurate can-gmg or tenstransfer mechanism; to rovi e improved and simplified product-registering means; to rovide an improved and simplified flexib e keyboard; to provide means whereby a mista e in the depression of either a multiplicand key or a multiplier key may be corrected at any time before the actual multiplication has occurred; to so arran e the machine that a product of one multip ication may be transferred to the multiplicand keyboard, for further multiplication ofthat product, before the machine is cleared; to provide simple and accurate clearing means; and generally, to make the machine relatively light and compact,'relativelg simple, easy to operate; eas to understan accurate; and ree from iability to derangement. Other objects of my invention will appear hereinafter.

I will now roceed to describe my invention. with re erence tothe accompanying drawings, and will then point out-the novel features in claims. In the drawings:

Figure 1 shows a top viewof a multiplying machine embodying my invention.

Fig. 1 shows a transverse vertical section through the keyboards of the machine, and Fig. 1" is a fragmentary section, on a plane parallel to that of Fig. 1, showing one of the zero keys'of the multiplicand keyboard.

Fig. 2 shows a side elevation of such machine, and Fig. 2 is a front elevation thereof.

Fig. 3 shows a vertical sectionof themachine from .front to rear on the section line M of Fig. 1, the carriage and upper rear portion of the machine being shown, in side elevation; the keys shown being those for setting up the multiplicand. I

Fig. 4 shows a vertical section from front to rear on the section line H of Fi 1,, the carriage and upper rear portion 0 the machine being shown in side elevation, and articular]; rack bars controlled by the mu tiplicand keys; the multiplier keys being shown behind the plane of section; portlons of the mechanism being omitted for clearness.

Fig. 5 shows a fragmentary transverse vertical section of the machine on the section line 00 of Fi 1, a. e. is a vertical transverse section t rough the multi lier keyboard of the machine; Fig. 5 is a ragmentary section on the same section line, showing one of the vmultiplier keys depressed; Fig. 5 shows a fragmentary transverse section on the line H of Fig. 5, and Fig. 5 shows a similar section on the line p'-p' of Fig. 5; Fig. 5 is a fragmentary top view of the bar 18; and Fig. 5 is a fragmentary side view of rack bar 27 and the lower k7e 's'when in depressed position.

ig. 6 is a detail elevation and partial transverse vertical section, showing two of ortion of one of the multiplier the multiplicand keys, one behind the other, and showing the rack bar which those keys control, and portions of the gear shift mechanism.

Fig. 6" is a detail horizontal section on the section line 9-9 of Fig. 6.

Fig. 7 showsa detail section, looking from the rear of the machine, on the irregular section line rr of Fig. 3, looking obliquel downward; that is to say, a section throng the centers of the dial wheel shaft, the idler shaft, the differential shaft, and the feeler shaft.

Fig. 8 shows a rear elevation of theprincipal parts shown in Fig. 7 looking obliquely downward.

Fig. 9 is a detail side elevation and partial section of a portion of one of the differential gear sets of the anism.

Fig. 10 shows an axial section of the parts product-transferring mechshown in Fig. 9.

. Fig. 11 shows a bottom view of the machine.

Fig. 12 is a detail elevation of a portion of the mechanism by which cams of the machine and the .rack bars of themultiplicand keyboard are moved.

Fig. 13 is a fragmentary side elevation and partial vertical section-of the lower portion of the machine, showing portions of the mechanism for operating the stepped product disks.

Fig. 14 shows a side elevation of one row of multiplicand keys and associated means for restoring each depressed ke upon the depression of another key, one side plate of the guideway having been removed; and Fig. 15 shows a front elevation of one of the multiplicand keys and a transverse section of the roller guideway employed in connectionwith that key.

Fig. 16 is a detail side elevation and partial section showing one of the stepped product disks, its corresponding rack bar, its corresponding feeler, and the mechanism for transmitting motion from that feeler to the for of. tens.

Fig. 17 is a similar view of the same partsosition for the transfer of tens. i 18 is a detail side elevation of one of the eelers.

Fig. 19 is a detail side view of a portion of the carrying or tens-transfer mechanism, cooperating with each feeler.

1g. 20 1s a rear view of the parts shown in-Fig. 19.

Fig. 21 is a side elevation of one of the feelers and the cam mechanism operating in connection therewith.

Fig. 22 is a rear view showin the first and last feelers of the machine (intermediate feelers being omitted for sake of simmechanism.

Fig." 24 is a rearview of the parts shown in Fig. 23, and Fig. 25 is a' view similar to Fig. 23, but showing the parts in a different position.

' Fig. 26 is a detail end view and partial section of a portionof the mechanism shown in Figs. 23-25.

Fig. 27 is aschematic view illustrating, diagrammatically, the action of the .cams on the feelers'and associated parts.

Fig. 28 is a detail front elevation and partial section of the carriage with dial wheels thereon and carriage return and dial resettin or clearing mechanism, the casing having een removed.

Fig. 29 is a vertical transverse section of the carriage and associated parts on the line 8-8 of Fig. 28, and shows carriage feed mechanism. d

Fig. 30 is a transverse section of the carriage and associated parts on the line e-'v of Fig. 28.

Fig. 31 is a detail elevation and partial section, taken from the left of Fig. 28, and showing a part of the clearing mechanism.

Fig.32 is a bottom view of a portion of the carriage feed mechanism.

Fig. 33 is a plan view of the parts shown in Fig. 28, with thedial wheels and dial shaft and certain other parts omitted for sake of simplicity.

Fig. 34 is a detail top View of the gate device employed in connection with the gear ing mechanism, the differentials of the gearing mechanism being shown in dotted lines.

Fig. 35 shows a side elevation of an alternative mechanism for transmitting motion from the main operating lever to the cams and other mechanism operated by that lever; Fig. 36 shows a fragmentary horizontal section of such alternative mechanism, and Fig. 37 an end view thereof.

Fig. 38 shows a fragmentary vertical section from front to rear through the multiplicand keyboard and associated parts, the upper portion of the carriage being shown in elevation; this view showing means for the restoration of the multiplieand keys by the return of the carriage, means for restoration of the multiplicand keys by the depression of a special restoring key, and means for interlocking the multiplicand keyboard mechanism and multiplier keyboard mcchanism to prevent depression of a multiplicand key after the multiplier operation has commenced.

Fig. 39 is a fragmentary transverse secciated tion of one of the multiplier keys and assovic'e 're erred to.

Fig. 40 is a fragmentary section on the plane of Fig. 38, showing one of the multiplier keys depressed and the other keys locked against depression.

Fig. 41 .is a fragmentary side elevation of a portion of the restoring mechanism shown in Fig. 38, the carriage being shown in side elevation.

arts includingthe interlocking de-gf' I Fig. 42 is a fragmentary vertical transverse section of a portion of the mechanism for the restoration of the multiplicand keys by the action of the carriage.

Figs. 43-47 inclusive indicate means whereby addition as well as multiplication 'Fig. 44 showing a side view, and partial section. of the carriage feed mechanism employed in such case, and associated parts, Figs. 45 and 46 being fragmentary vertical, sections, on a plane at right angles to that of F ig. 44, showing the automatic key resetting mechanism in different positions: and Fig. 47 being a fragmentary top view of a portion of the keyboard top plate showing the locking notches for the feed-shift lever.

In my multiplying machine shown in the accompanying drawings there is a multiplicand receiving device, which in the construction shown is a keyboard, and a multiplier receiving device, which in the construction shown is also a keyboard, the two keyboards being arranged side by side; together with a movable carriage, mounted in a manner similar to an ordinary typewriter carriage,

except that the carriage moves, during multiplication, from left to right, whereas the carriage of an ordinary typewriter moves from right to left. This carriage carries dial wheels showing products. The multiplicand keyboard comprises a plurality of columns of keys, each comprising in general keys numbered from O to 9 inclusive. the number of such columns depending upon the intended capacity of the machine; and there may be a greater or a less number of such columns of keys according to the intended capacity of the machines. The multiplier keyboard comprises, in general, a single column of keys, from 0 to 9 inclusive. Associated with each multiplicand key is a gear wheel, adapted to mesh with a rack beneath and common to all of the keys of that column; each of such gear wheels arranged to be thrown into mesh with its corresponding rack when the corresponding key is deressed; and the gear wheels of the different iieys of each multiplicand column are (ex cept as hereinafter stated) of different pitch diameters, corresponding to the numerical values of their respective keys. These gear wheels are inter-connected so that they rotate at the same rotative speed, (except as hereinafter stated), the extent of their rotation being proportional to the numerical of the stepped disk corresponding to the products of the multiplication of different multilicand digits, by different multiplier digits. Each stepped disk is double, the steps of the lower member of the stepped disk corresponding to the digits of the-lower order of the product, the steps of the upper member of the stepped disk corresponding to the digits of the higher order of the product. Associated with each such double stepped disk there are two pivoted feelers, one for each member of the stepped disk, each feeler having a portion adapted to be brought down, into engagement with the particular stepped disk step which is brought into registering position with reference to that feeler bythe operation of the corresponding multiplicand and multiplier keys; and on each such feeler is a gear segment intermeshing with a gear of a gear train whereby the corresponding dial wheel is rotated. The actuating mechanisms corresponding to the dial wheels of all" but the highest or left hand product digit comprise suitable carrying mechanism or tenstransfer mechanism whereby when necessary tens of the product are carried over into the next dial wheel above. It will be seen that any suitable multiplicand within the capacity of the machine may be set up by depressing proper multiplicand keys; and that when a multiplier key is depressed and the gear wheels of the multiplicand keyboard thereafter caused to rotate to an extent de pendent upon the numerical value of the multiplier key; so depressed, the rack bars corresponding to the multiplicand keys so depressed are each moved to an extent proportional to the product of the numerical. value of the corresponding depressed multiplicand key by the numerical value of the particular multiplier key so depressed.

Such. movement ofthe rack bars, proportional to the said products, are transmitted by the rack bars to the stepped disks mentioned, and then the feelers pertaining to such stepped disks are brought down against those steps of such stepped disks presented to such feelers by the particular degree of this numeral is app rotation which has been imparted to each star wheel. The succeeding return motion of the feelers. in turn imparts motion, through gear trains, to the dial wheels on the carriage. I

A multiplier,'naturally, often consists of two or more digits; for example, the multiplier may be 1 2 4. In such case after the multiplicand has been set up, the 4. multiplier key will be depressed and the mechanism of the machine operated; the carriage then steps one step to the right (in practice, thisstepping is effected in two half steps; as will be explained later) the 2 key of the multiplier keyboard is then depressed and the mechanism of the machine operated; the carriage then steps a further step to the right; the 1 key of'the multiplier keyboard is then depressed, and the mechanism of the machine operated; whereupon the product of the multiplication will appear on the dial wheels carried by the carriage. By such stepping ofthe carriage to the right, compensation is made for the particular column to which the digit of the multiplier belon s. Means are provided, as hereinafter escribed, for clearin the machine after each one column of keys numbered from 0 to 9 inclusive. 0 designates the carriage carrying the dial wheels D; the carriage being mounted to move laterally in suitable wa s E (Figsy29 and 30),.the mountingof t e carriage being similar to that of a typewriter carriage, and the particular details of this mountlng being unimportant.

Multiplicand keyboard.

Numeral 1, (Fi s. 1, 2, 3 and 6) designates one of the eys of the multiplicand keyboard (the fourth or 3 key of one of the columns). The particular key to which ied is immaterial, and the operation of t e other keys of the multiplicand keyboard and-associated parts is entirely similar in principle, and is exactly similar in effect, (except in a minor respect relating to the 1 and 2 keys, as hereinafter explained). Beneath each row from front to rear of. keys of the multiplicand keyboard there is a rack bar 2 mounted to slide from front to rear and intermeshin with a pinion 3 on a transverse shaft 4; eac such pinion 3 being secured to a corresponding two-part stepped product disk 5-5 (in practice each such plnion 3 is located between the two parts 5 and 5 of its correparticularly in'Fig. 11). Below, and normally out of mesh with the rack bar 2, are

' gears 6 and 6, one for each key corresponding to that rack bar; such gears being axially movable into and out of mesh with the corresponding rack bar and, in normal positions, being alternately to the right and to the left of the corresponding rack bar. Each key is provided with a lever mechanism 78 for throwing the corresponding gear 6 or 6 into and out of mesh with the corresponding rack bar 2; each such lever 8 being pivoted at 9 to a stationary portion of the frame of the machine, and the pivotal connection of each lever 7 to the corresponding key 1 being aboveits point of pivotal connection to the corresponding lever 8 when that key is inelevated position, and being preferably, somewhat below such point of pivotal connection to lever 8 when that key is in depressed position; so that, each lever 9 having a coil spring 10 as shown particularly in Fig. 6, the reaction'of the spring tends to hold such key 1 in either its elevated or depressed position, according as the key has been left in its e]evated or depressed position. In Fig. 6 I haveshown one key, 1, in depressed positioirt. and behind it another key, 1, in normal orelevated position; the gear 6 of key 1 being in mesh with rack bar 2, and the'gear 6 ofv key 1', being out of mesh with rack 2. 'As shown particularly in Figs. 6, 14 and l5,..each key 1 works, at its lower end, in a giii'dewa'y l'l, wherein are guide rollers 1212' andrestoring rollers 13; the lower end ofeach key, 1, being pointed as shown, for enga ment with the peripher of one of the" rol ers 13.-

When one .of the eys 1 has been depressed, it moves to one. side the rollers 13, and

thereby cams upward, or restores, that key,

if any, which was previously depressed. This constitutes what is termed a flexible keyboard mechanism which is simpler than any other flexible keyboard mechanism of which I am aware; and which constitutes one feature of my invention.

Multiplier keyboard. and mechanism transmittz'ng motion toctepped star or product wheels.

Referring now for the moment to the multiplier keyboard, (Figs. 5-5", inclusive) Numeral 14 designates one of the multiplier keys (it. is immaterial to which key reference is made, the particular key to which that numeral is applied in Fig. 5 being the,

6 key). These keys 14 are mounted to movevertically (and also to have a slightoscillating motion) and are suitably guided by slots in guide frames 15 and 16; and

' springs 17 tend to hold .these keys 14 elevatedi Associated with keys 14 there is a longitudinally movable bar 18 mounted-upon pivoted links 19 and 20; and this bar is provided with studs 21 and 22, for each key, the stud 21 adapted to coact with the projection 23 of the key bar, and the stud 22 adapted to coact with recesses 24 and 25 of the key. When one of the keys 14 is depressed, the cam projection 23 of such key, engaging the stud 21 of the bar 18, moves that bar to the right (as the parts are viewed in Fig. 5) thereby raising a locking lever 26 partly outof the path of an operating rack bar 27; Fig. 5 shows the locking lever 26 in' such position. This movement of the bar 18 brings the studs 22 offche bar 18 into engagement with the recesses 24 of all the keys, except that key which has been depressed, and except the zero' key 14, the stud 22 for whichis more distant from its key than are the studs 22 for the other keys. The reason for this will be explained later. Engagement of the studs 22 with the keys 14 other than that key which. has been depressed, locks such other keys 14, preventing the simultaneous depression of two keys 14. The stud 22 correspondingto that key 14 which has been depressed enters the notch 25 of that key,

such notch 25 being provided merely to permit movement of thevbar 18.

A gear 28 intermeshes continuously with rack bar 27. This gear 28 is rotated, after are viewedin'. Fig. 5) until that rack bar is arrested by engagement of a stud 29 on such rack bar with the key 14 which has been depressed. The rack bar 27 in so moving, engages the beveled lower portion 26* of lever 26, thereby raising such lever and, in so doing, moving bar 18 to the rlght far enough to bring the stud 22 corresponding to the 0 key 14 into engagement with the recess 24 of that key. The rotation of gear 28 (Fig. 5) is caused by rotation of. the shaft 30 on which that gear 28 is mounted. The hand lever 31, before referred to as the means by which shaft 30 is caused to rotate, is shown in Figs. 1,

2, 2, 23 and 24. This hand lever operates,

through intermediate mechanism to be described hereinafter, a lever 31 (Fig. 13)

connected by a push rod 32 to a gear sector 33 which intermeshes with a gear 34 on the 1 shaft 35 of the multiplicand keyboard and with a gear 36 of the 2 shaft 37 of the multiplicand keyboard, and with a gear .38 (Fi 11) on the 3 shaft 39 of the vmultip icand k b d The 5, 6, etc. shafts 40, 40 40, etc. of

the multiplicand keyboard, are driven from gear sector 33 and gear 39 on shaft 39, through a rack bar 41 and suitable pinions 42, 42, 42" etc. Therefore, the shaft 39 and the shafts 40, 40, 40, etc, all rotate at the same rotative speed. The final inion 42, of the series of pinions'or gears lntermeshing with rack bar 41, is on the shaft 30 above mentioned, so that this shaft 30 (which might also be termed shaft 40") rotates at the same speed as the shafts 40, 40, 40, etc. When any one of the keys 1-9 inclusive of any one or more of the columns of the multiplicand keyboard is depressed,

therefore, and its corresponding gear (3, or,

6, is brought into mesh with the corresponding rack bar 2 of the multiplicand keyboard, and when one of the multiplier-keys 14 (Fig. 5) has been depressed, and then the lever 31 is operated, so moving the gear 7 sector 33 (Fig. 13) and thereby moving the various shafts 39, 40, 40, 40, etc., and 30, and thereby causing these shafts to rotate until such rotation is stopped by engagement of the stud 29 of rack bar 27, with that multiplier key which has been depressed, it will be clear that the rack bar or bars 2 of the multiplicand keyboard corresponding to the key or keys of the multiplicand keyboard which have been depressed, will each be moved a distance corresponding to the product of the numerical value of each such multiplicand key which has been depressed, by the numerical value of the multiplier key which has been depressed; for, the motion of the rack bar 27 of the multiplier keyboard is clearly proportional in distance to the numerical value of that multiplier key which has been depressed; and, as has been stated previously, the depression of any key of the multiplicand keyboard throws into 'mesh with the corresponding rack bar 2 a gear 6, or

6, of a pitch diameter proportional to the numerical value of that multiplicand key depressed, (and as has been shown previously, these gears 6 and 6 all rotate at the same rotative speed, with the exception of the gears on the shafts corresponding to the l and 2 shafts of the multiplicand keyboard, to which reference will be made presently).

Since, as just shown, upon the depression of a ke of one or more of the columns of the mu tiplicandkeyboard, and the depression of a key of the multiplier keyboard, and the operation of the lever 31, the rack bars 2 corresponding to the several multiplicand keys depressed, are each moved a distance proportional to the product of the numercial value of the corresponding multiplicand key depressed multiplied by the numerical value of the multiplier key depressed, each rack bar 2 causes rotation of its corresponding double stepped product not disks corresponding to the numerical value of the product of the digitof the corresponding m'ultiplicaml key depressed by the digit of the corresponding multiplier key depressed, motion corresponding in amplitude to such product may be trans mitted by the gear segments of such feelers, through intervening gearing, to the appropriate dial wheels of the carriage.

Since some products of multiplication of.

one digit by another may be represented by a single digit (for example 3x3) while other products of one digit by another are represented by two digits (81 being the highest product of any one digit by another digit) I have found it convenient to employ, in connection with each rack bar 2 two stepped product disks, viz:5 and 5*. The first lobe M of each disk 5 carries steps of a value corresponding to '0' to 9 inclusive (1'. 0., the

products of the multiplication of digits 0 to 9 inclusive by digit 1) the next lobe lfi of each product disk 5 carries steps corresponding in nlnnerical value to the lower order digit of two digit products of whichthe higher digit is 1; while a corresponding lobe of the associated-product disk 5* is provided with a step corresponding in numerical value to l; the third lobe of product disk 5' carries steps corresponding in numerical value to the lower order digit of two-digit products of which the higher digit is 2, while a corresponding lobe of the associated prod uct disk 5 is provided with a step corresponding in numerical value to 2; and so on. Of course, it is unnecessary to provide the stepped product disks 5 and :5 with steps corresponding to prime numbers (c'. e. numbers which are not divisible). By employing two associated product, disks, 5 and 5*, corresponding to each rack bar 2-, 4.6., corresponding to each column of the multiplicand keyboard, and by employing corresponding feelers 43 and 43, and suitable carrying mechanism, as hereinafter described, I am able to transmit to the dial wheels of the carriage the product of the multiplication of the numerical value of any mu-ltiplicand key or keys depressed, by the numerial value of any multiplier key depressed.

I Thehand lever 31 previously referred to 68 (Fig. 23). The mechanism by which motion is communicated from lever 31 to gear 68, includes means, hereinafter described, whereby a complete rotation of the gear 68, without overthrow, is assured for each operation of lever 31. This gear 68 is on, and drives, a transverse cam shaft 69.

Transfer mechanism, dial wheels and carm'age.

Referring to Figs. 3, 4 and 7-10 inclusive.

As shown particularly in Fig. 7, the gear segments of the feelers 43 and 43*.mesh respectively with pinions 46 and 46 which are loose on a shaft 47; except that the first gear of the series, 46*, is fixed upon the shaft 47, and there is no feeler for this first gear 46*. Each gear 46, or 46, drives another gear, 48, (there being one gear 48 for each pair of gears 46 and 46) through a planetary gear, 49 or 50' (Figs. 9 and 10) the gear 49 being in mesh with the gear 46" on the left hand side (as viewed from the rear) of corresponding gear 48, and the gear 50 being in mesh with the gear 46on the right hand side of the corresponding gear 48, (gears 49 and 50 being in mesh with each other). Gears 49 and 50 are mounted in bearings on brackets 51 carried by gear 48. It will be clear, since gears 49 and 50 are planetary gears, that rotation of either a gear 46, or of a gear 4'6, associated with any particular gear 48, will cause corresponding rotation of that gear 48, through e planetary gear 49, or 50, as the case may be; and it will also be'clear that both gears 46 and 46, associated with any particular gear 48, can be operated simultaneously,

with summation effect on the corresponding gear 48. Thus, supposing a. gear 46' associated with a articular gear 48 to remain stationary whi e the gear 46 on theiopposite side of such gear 48 is rotated, rotation of such gear 46 will drive planetary pinion 50,

and so will drive gear 48, planetary pinion 49 rolling idly about gear 46; and similarly vif gear 46 be rotated while the corresponding gear 46 is held stationary, pinion 49 will be driven and will drive gear 48 while planetary pinion 50 will rotate idly about gear 46; while if both gears 46 and 46 associated with any particular gear 48 be rotated, then both planetary pinions 49 and 50 are driven, and gear 48 is given a movement which is the sum of the movements Igiven to use the term differential gear set to designate the.

it by planetary pinions 49 and 50.

gear sets each comprising a gear 48, driven by gears46 and 46 through planetary gears 49 and 50, There is one such differential gear set for, and arranged to drive, each dial wheel of the carriage.

Of the two feelers, 43 and 43, associated With any particular rack bar-2, feeler 43 65. actuates the gear 46 of the planetary set which drives the dial wheel corresponding to that rack :bar,.wl1ile feeler 43 actuates the gear 46 of the planetary set next above or to the right (as viewed from the rear of the machine, in Fig. 7) z'. e., of the next higher order or place, in this way any motion of a feeler 43 has, with respect to the result as indicated on the dial wheels, ten times the effect of a corresponding movement of the associated feeler 43. i

The final gear 48 of each differential gear set intermeshes 'With an intermediate gear 52 (see particularly Figs. 29 and 30) on a shaft 53 carried by the carriage C; and each gear 52 intermeshes with a dial-wheel gear 54 mounted upon a shaft 55 also carried by the carriage, and fixedly connected to a corresponding dial wheel 56 also mounted upon shaft 55. These dial wheels carry numerals 0-9 inclusive; and in the particular arrangement shown, each dial wheel carries two successive series of numerals 09 inclusive.

The operation of transferring the motion of the rack bars 2 and corresponding stepped product disks and 5 to the dial :wheels of the carriage is, in part, as follows:

Supposing one or more of the double stepped product disks 5 and 5* to have been .rotatedby the corresponding rack bar or bars 2, to a position or positions representing some partial roduct, then at a proper point in the rotation of shaft 69, (such rotation being. caused, as hereinafter described, by operation of hand lever 31) the cams 156 and 157 (Fig. 21) for'actuating the feelers 4343" cause a frame 151-152159 hereinafter mentioned (see Fig. 22) to move,

down, thereby moving down member 151 of such frame, (which as shown in Fig. 16, normally engages shoulders 150 of all of the .feelers,) and so permitting the springs 158 of the several feelers to draw those feelers down each into engagement with that por- -151-152159 back to normal position and.

so cause member'151 of-that frame to move these feelers backward to normal position v and the gear sectors of the feelers in such reverse motion communicate motion to the gear sets;- and the resulting motion of the 4 gears 48 of the differential gear sets, is com 

